Process of making wool-like cellulosic textile materials stabilized against photodegradation



United States Patent 3,053,606 PROCESS OF MAKING WOOL-LIKE CELLULOSIC TEXTILE MATERIALS STABILIZED AGAINST PHOTODEGRADATION Hugh C. Gulledge, Newark, Del., assignor to E. I. du Pont de Nemours and Company, Wilmington, Del., a corporation of Delaware No Drawing. Filed June 2, 1958, Ser. No. 738,965 14 Claims. (Cl. 8-115.6)

This invention relates to the production of novel, metallated cellulosic materials, and more particularly to the preparation of improved titanated cellulosic materials adapted for use in the textile industry.

This application is a continuation in part of my co pending application Serial No. 512,308, filed May 31, 1955, and which is now abandoned.

Various cellulosic materials, including fibers, films, sheets and coatings, both synthetic and natural, can be treated to improve their properties. Thus, cotton or other cellulosic material can be treated with certain titanium or zirconium compounds to obtain a titanated or zirconated cellulosic product exhibiting improved properties in respect to, for example, flame resistance, high melting point and greater resilience. The simple combination, in approximately molecularly dispersed dimensions, of the metallating compound with the cellulose results in a disadvantageously unstable product, with the instability being generally related to photochemical. activity. Thus, when titanated cotton is exposed'to sunlight or other similar radiations, its tear strength characteristics rapidly decrease. In addition, dyeing of the titanated cotton or other titanated cellulosics presents a problem due to a lack of dye color stability. The first of these difliculties can largely be overcome by resorting to the expedient of combining antimony with titanium in the cellulose treatment. quantities of expensive antimony oxides and the confronting problem of dye stability in the remaining product will be found to still remain.

It has now been found that these disadvantageous properties of metallated cellulosic materials especially titanated or titanated and antimonited for-ms thereof, can be effectively overcome, and a principal object of the invention is to provide novel methods and means for attaining such result. It is among the particular objects of the invention to provide novel, relatively stable forms of metallated cellulosic products, especially fibers and textiles possessing wool-resembling properties and which exhibit improved crease resistance, increased liveliness, mildew resistance, flame resistance, greater warmth and insulating properties, washability, high melting point and other desirable properties; to provide novel methods for converting inexpensive forms of cellulose Such as cotton to more useful products competitive with wool; and to provide novel methods for obtaining an improved metallated or titanated cellulosic product in which the treating metal such as titanium is in chemical combination with the cellulose which product is resistant toward photodegradation and advantageously possesses improved tensile strength and dye color stability characteristics. Other objects and advantages of the invention will be apparent from the ensuing description.

These objects are attained in this invention which comprises stabilizing a metal modified amine-swollen cellulosic product by subjecting it to the action of an aqueous solution of a salt of a heavy metal to intimately associate with said product a substantiallywater-insoluble, oxygenated compound of a heavy metal.

In a more specific embodiment, the invention comprises stabilizing against photodegradation a modified cellulose textile material exhibiting substantially the single fiher,

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liveliness, crease resistance, mildew resistance and bulk characteristics of wool, by subjecting an amine-swollen form of the cellulosic product after metallation to combine therewith antimony and from, preferably, about 5- 30%, calculated as the oxide, of a metal from the first subgroup of group IV of the periodic table, such as titanium or zirconium, to treatment with an aqueous'acidic solution of a salt or a polyvalent heavy metal such as antimony, chromium, cobalt, copper, etc., and thereafter precipitating or coalescing on the material a relatively minor amount of an insoluble oxygenated compound of i said polyvalent metal by reducing the acidity of said solution.

In describing the invention, treatment of a modified,

metallated, especially a titanated form of cellulosic prodnot having the properties mentioned and prepared in accordance with the disclosures of my copending application Serial No. 707,870 (now U.S. Patent No. 2,980,490) or Serial No. 707,857, now U.S. Patent No. 2,980,489, both filed January 9, 1958, will be referred to. The product can be prepared by wetting, immersing or otherwise treating under liquid phase conditions in a reactor, a textile or other desired form of cellulosic material, e.g., cotton, rayon, linen, ramie, etc., at room or elevated temperatures for a minimum of about 30 minutes with a suitable anhydrous nitrogenous (-NH or NH radical containing) swelling or complexing agent, e.g., liquid NH or the alkyl or aryl derivative thereof, including alkyl amines (ethyl amine, methyl amine, ethylene diamine, dimethyl amine, etc.), aryl amines (phenyl amine, methyl phenyl amine, phenylenediamine, naphthylamine, etc.) until desired preswelling, conditioning or complexing of the cellulose is attained. Excess agent is then drained or otherwise suitably removed from the swollen, complexed amine cellulose and the product is then immersed and heated for at least 15 minutes, preferably at the boil, in a suitable solution of an anhydrous hydrolyzable organic metal ester, particularly an alkyl or aryl metal ester of the ortho type, until transfer of the metal from the solu tion to the cellulose becomes effected and formation of a highly tendered metal ester-amine cellulose intermediate results. This intermediate is then separated from the organic liquid and regenerated by treatment or immersion in water or other aqueous media such as an alcohol or other organic solvent containing water adapted to remove the hydrolysis product of the intermediate and leave the metal radical in reacted condition within the cellulose structure as a cellulose derivative having substantially the macroscopic shape, tensile strength, Washability and high melting point of the original fibrous cellulosic material from which it is derived. The material will contain from about 2% to 40% or more of the metal, calculated as the oxide, and usually from about 3-35% of metal oxide. Preferably, the amount of TiO or other metal oxide present ranges from about 1030%. In addition to the other advantageous properties the product will possess improved abrasion and mildew resistance, have the single fiber characteristics of wool (including initial modulus, compliance ratio, work recovery, crimp elongation), and such desirable Wool-like woven cloth properties as handle and high crease resistance.

Metal esters useful in the metallation comprise the compounds or mixtures disclosed in said copending applications. As set forth in said application Serial No. 707,870, they can correspond to the formula Me(OR) in which Me includes titanium, zirconium, hafnium, thorium, aluminum, iron (ferric), etc., e.g., metals which form water insoluble oxides and have a coordination number at least one greater than the valence of the metal in the oxide form (which number is usually 6), R is a monovalent hydrocarbonor chlorinated hydrocarbon radical, such as an alkyl (methyl, ethyl, chloroethyl, propyl, butyl, amyl, isopropyl, etc.), cycloalkyl (cyclobutane, cyclopentane, cyclohexane, cycloheptane, etc.), aryl (phenyl, benzyl, napthyl, etc.), alkaryl (tolyl, xylyl, ethyl phenyl, propyl phenyl, etc.), aralkyl (benzyl, phenyl-ethyl, phenylpropyl, etc.), and x is 3 and 4, the valence of the metal in its highest state of oxidation. For reasons of economy, esters having the smaller alkyl radicals (1-6 carbon atoms) are preferred for use, such as methyl, ethyl, propyl, isopropyl, butyl, pentyl and benzyl. Generally, however, compounds containing an alkyl hydrocarbon of an alcohol having from say, l-12 carbon atoms in its chain will be found to be especially useful. Preferred for use also are tetraalkyl titanates and zirconates, such as tetrapropyl titanate, tetrabutyl titanate, tetraisopropyl titanate, tetraethyl titanate, tetrabutyl zirconate, tetramethyl zirconate, tetrapropyl zirconate, etc. Specific examples of other useful esters include triethyl aluminate, tn'butyl aluminate, triethyl ferrate, etc., and the various tetraethylates, isopropylates, butylates, hexylates, decylates, ethylates, cyclohexalates, phenolates, benzylates, betanaphthalates, etc., of the metals mentioned and their monochloro derivatives. The ester can be used as either a pure liquid or as a solution in an organic solvent (alcohol, benzene, toluene, xylene, cyclohexane, etc.). Alternatively, and as disclosed in said copending application Serial No. 707,857, hydrolyzable antimony esters, such as the various antimonates and antimonites can be used. They correspond to the formula (RO) Sb, wherein R is a monovalent hydrocarbon radical, such as the various alkyls, aryls, aralkyls, cycloalkyls mentioned above, e.g., methyl, ethyl, propyl, butyl, cyclopropyl, phenyl, naphthyl, tolyl, anthranyl, benzyl, xylyl, ethyl phenyl, phenyl propyl, etc., as well as the monochloro and dichloro derivatives of these compounds. Especially useful are trialkyl antimonites in which the hydrocarbon radical contains from 1-12 and preferably from l-6 carbon atoms. Examples thereof include trimethyl, ethyl, isopropyl, butyl, hexyl, octyl, benzyl, phenyl antimonites and their various mixtures. These esters are applied under substantially anhydrous conditions, although the presence of small amounts of water, as indicated in connection with the titanium esters, can be tolerated. The antimony ester is preferably used in combination, that is, sumultaneously with the titanium or zirconium esters, or they may be applied sequentially, e.g., before or after the titanating step, but prior to the water-washing step.

In accordance with this invention, the cellulosic product resulting from the metallations mentioned is stabilized against photodegradation and improved in other desirable respects by treating it during or after the regeneration step, and preferably while it is in amineswollen metalized state, with an aqueous acidic solution of a polyvalent metal salt or mixtures thereof so as to precipitate, adsorb or coalesce on the regenerated product a small amount, say from about 1-15%, calculated as the oxide, of an insoluble basic compound, such as an oxide, hydroxide or hydrous oxide of the polyvalent metal or metals present in such solution. Metal salts contemplated as useful for this purpose include the chlorides, bromides, nitrates, sulfates, acetates, formates, etc., of metals such as antimony, chromium, manganese, cobalt, nickel, bismuth, copper, tungsten and the common rare earths, especially cerium, etc. Of such salts, those of antimony are preferred for treating white products, and these are employed in such concentration as will associate from 542% of say Sb O with the cellulose. Lesser amounts, say from 1-3% can be associated with the cellulose when other treating salts are employed. In such treatment, the metallated product can be immersed in or otherwise wetted, at room (2025 C.) temperatures or generally at from 5750 C., with a relatively dilute (say from about l-20%) solution of the salt and until the interstices of the product become completely permeated therewith. The metal ions are usually strongly adsorbed from solution by the titanated cellulose so that simple washing will remove the anions and leave a stable metal treated product. However, to further promote the magnitude and efficiency of the treatment the pH of the solution is preferably adjusted by neutralization or thorough washing out of acid to remove anions of the metal and to coalesce an insoluble compound of said metal on the cellulose. Alternatively, the initial impregnation can be accomplished by passin the product between suitable rollers coated or wetted with the salt solution. Thereafter, excess of salt solution can be removed by draining, centrifuging or passage of the wetted material through nip rollers. Neutralization or thorough washing can then be undertaken and adjustment of the pH to induce the desired precipitation. This can be accomplished by passing it through an aqueous alkali solution, such as caustic soda, potassium hydroxide, ammonia, sodium carbonate, etc., which will effect the necessary acidity reduction and absorb or impregnate the final cellulose product with the requisite type and amount of after-treating metal compound or compounds. The precipitating bath can also be maintained at room temperature, but may be lower or higher, as desired. After precipitation the textile can be conventionally washed to remove excess products and by-products of the reaction and the stabilized, non-tendering product is then recovered.

To a clearer understanding of the invention the following specific examples are given. These are merely illustrative and are not to be construed as in limitation of the invention.

EXAMPLE I Portions of a 40s 2 ply cotton yarn were packed into wire baskets and placed within a reactor vessel adapted to retain a liquid under pressure. Cooling means and means for circulating a liquid contained therein through the yarn were provided in such vessel. The reactor was then closed and monomethyl amine was valved in and the yarn immersed therein for a period of one hour at 10 C. Free liquid amine was then drained from the vessel and an isopropanol solution of tetraisopropyl titanate and triisopropyl antimonite, analyzing 10.3% TiO and 1.7% Sb O was then circulated through the yarn for a period of one hour at 25 p.s.i.g. while a temperature of C. was maintained. The metallating solution was then drained away, and the yarn was washed twice with dry isopropanol and removed from the vessel. The resulting yarn product was in a highly tenderized state and was then immersed in water, further washed to remove isopropanol and amine, and dried. The recovered dried yarn containing on analysis 16% TiO and 6% Sb O was converted by conventional procedure into a 50 x 45 5.8 ounce plain weave cloth fabric. 22 swatches were cut from this cloth. 6 of these were dyed bluish gray with an olive G dye, while another group of 6 were dyed yellow with a vat flavone GCN dye. The dyes were applied to the fabric by conventional vat dyeing procedure, using a 4 oz./gal. of dye solution. 10 of the dyed and 10 of the undyed swatches were after treated with the metal salt or salts indicated in Table I below, by dissolving 5 grams of the salt per liter of water and soaking the swatches for one hour in the salt solution. In the instance of salt mixture use, 3 grams of each salt were disoslved in one liter of water. Following such treatment the fabric was removed, given one quick rinse in water and acids present neutralized through immersion in a 3% ammonia solution. Each such swatch was then washed and dried.

The 10 undyed, salt-treated swatches were then dyed similar to the two groups of 6 mentioned, leaving two dyed, non-salt treated swatches as controls. In the table below, therefore, 20 sample swatches containing TiO and Sb O in the amounts mentioned and after-treated as indicated opposite each, both before andaftef dyeing are shown, along with 2 non-after treated swatches.

All of these swatches were then subjected to exposure testing, with Observances being made at 20 and 40 hour intervals, in a standard Fadometer testing machine with the following results:

Table I Fade-O-Meter Test Salts Olive G Flavone GCN 20 hrs. 40 hrs. 20 hrs. 40 hrs.

CrAcsH O:

3Y 4Y 4Y 4Y 0 0 l 1 SF 4F 3F 4F 2F 3F 2Y 3Y 1 1 2Y 3Y 0 1 0 1 3D 4D 4D 4D 0 0 0 0 A 2F 2F 2F 2}? No after treatment BY 4Y 4D 4D B =salt treatment before dyeing. A=salt treatment after dyeing. 0=no change. l=very slight change. 2 =slight change 3=readily noticeable. 4=very pronounced change. Y=yellowe F=faded. D darkened.

EXAMPLE II Samples of a cotton fabric and a yarn were titanated as described in Example I but with a solution of tetraisopropyl titanate in isobutanol containing Ti0 but no antimony. These were subjected to a series of aftertreatments and exposures to determine the resistance to tearing and breaking. Analysis before after-treating showed the yarns contained 19% TiO and the fabric 14%. The titanated samples were after treated with metal salts shown in Table 11 below by being immersedfor a short time in boiling solutions of the salt in the concentrations shown in such table. Following this, they were immersed in a 10% sodium hydroxide solution at room temperature to neutralize acids and precipitate the treating metals. Tear strength values were determined for the fabrics as tested on a standard Elmendorf tearing tester described in Standard 414M-42. of the Technical Association of the Pulp and Paper Industries, and are stated in terms of gram centimeters per centimeter of tear. The breaking strength given for the yarn is the number of grams of load per denier required to break the sample. The exposure values given are based on direct weathering and exposure of the sample to Delaware sunlight at a 45 angle on test fences facing south. In some cases, both the yarn and fabric were given the same treatment.

1 Soaked 20 minutes at room temperature and neutralized with NarCOa solution.

6 EXAMPLE III A sample of dry cotton duck was placed in a flask provided with facilities for receiving and discharging reagents without contamination from atmospheric moisture. Suflicient anhydrous ethylamine was run into this flask to cover the cloth and was allowed to reflux overnight. The amine was then drained from the resulting swollen cotton product, rinsed briefly with anhydrous isopropyl alcohol. Suflicient 20% solution of tetraisopropyl titanate in isopropanol was then placed in the flask to cover the cloth. After about four hours, during which time the temperature was raised to about 60 C., the isopropanol solution was drained off and the cloth was again washed with a little isopropanol. The amine swollen titanated cloth was then in a highly tenderized or fragile, almost gelatinous condition. This product was carefully removed from the flask and a portion of it was immersed in an aqueous solution of cobalt acetate containing 10 grams of cobalt acetate per liter. After the regeneration of the original stable fabric form the cloths were squeezed to remove excess solution and immersed in a 5% sodium carbonate solution. The remainder of the tenderized cloth was immersed in plain water. They were then laundered and dried, contained 18% of TiO and the salt-treated sample contained suflicient precipitated cobalt compound to render it pale pink in color. The initial tear strength of the fabric when measured by the Elmendorf tear tester was about 3000 grams cm./cm. The salttreated portion of the titanated cloth gave substantially the same value in this tester. Both the cobalt treated and the noncobalt treated titanated portions were subjected to weathering and sunlight exposure for six weeks at the end of which period they exhibited, respectively, tear strength values of 2100 and 1000.

EXAMPLE IV A sample of amine swollen and titanated cotton duck was prepared as in Example III. A portion of the water regenerated product Was immersed in a solution of CoAc containing 10 g. of salt per liter. After 15 minutes of soaking with mild agitation, the cloth was washed until the washings were substantially neutral and then dried. Analysis showed that about 3% C00 had been adsorbed in the cloth. Exposure tests on dyed samples of this product showed markedly better color retention for the cob alt containing fabric.

' As noted above, the invention is particularly adaptable in reactions of a titanium ester such as a tetraalkyl tita-t nate with an amine swollen cellulosic material to obtain a textile having novel wool-like crease-resistant properties. In such reaction antimony esters can be included to obtain the combined effect of titanium-antimony in imparting flame-proofing and resistance to photodegrada tion. These propenties arise when oxygenating titanium or metal compounds are in extremely finely or substantially molecularly dispersed state in or reacted with the cellulose which is not the case when the metal oxides consist of particles of pigmentary dimensions or larger.

The method of applying and dispersing the metals within the cellulosic fiber can be varied, and will depend upon the quantity required to obtain the results being sought and the nature of the cellulosic material. While generally applicable to metallated films, coatings and other forms of cellulosic products, those containing combined titanium, zirconium or antimony, etc., are especially benefited herein. The greatest usefulness of the invention is in its application to fibrous forms of the metallated cellulose, particularly textiles. Thus, in addition to titanatedcotton, linen, ramie, rayon and cellulose ester products, salt treatment can be had of any metallated cellulosic material, textile, fiber including metallated natural cellulose such as cotton, artificial silks from regenerated cellulose fibers and from either viscose, cellulose, acetate, nitrocellulose or cuprarnmonium manufacturing processes herein used is made of such derivatives as cellulose esters (acetate, formate, butyrate, etc.).

The quantity of salt or precipitated metal compound incorporated in or intimately associated with the cellulosic material, textile or yarn is not limited. Generally, rela tively small amounts or as little as possible are, for reasons of economy, resorted to. Furthermore, most of the utilizable metals impart color changes in the final product which restricts the amount to be employed. This factor bears importantly on or governs the quantity of salt treatment to be undertaken and the amount of metal compound to be precipitated in the after treatment. Preferably, the after treatment is applied to metallated cellulose before it is subjected to normal laundering, washing or dyeing. In some instances it can be applied in conjunc tion with preparation of the initial metallated cellulose. For example, when amine swollen cellulose is reacted with a titanium ester, such as tetraisopropyl titanate, a very fragile swollen gelatinous product results. This process is carried out under anhydrous conditions and the original form of the relatively strong durable material can be regenerated by subjecting the amine swollen titanated intermediate to contact with water. In the preferred embodiment of the invention the after treating salt is dissolved in the water used for the regeneration, and neutralization with an alkali, such as caustic soda, ammonia, or sodium carbonate is then efiected to reduce the acidity and precipitate and impregnate the cellulose material with the after-treating compound. Altenatively, the after-treating salt can be applied following the pure water regeneration of the swollen titanated cellulose, or even after the titanated cellulose have been washed and dried.

In Table I the salt treatment of the titanated cotton is undertaken prior to dyeing and gave consistently improved results with respect to stability of the dye color on exposure. Generally, I prefer this mode of procedure. In Table II the control sample is titanated but contains no antimony. Absence of the latter accounts for its extremely low tear strength after exposure. The salt treatment used therein, even when applied in quite dilute solutions will be found to advantageously greatly improve tear strength. Where antimony is present as in the sample shown in Table I, further treatment with such a salt results in improved desired resistance to photodegradation.

The quantity of precipitated metal compound incorporated in or intimately associated 'with the textile or yarn is not limited but variable. As stated, relatively small amounts are used. Operatively useful amounts range from .05% to calculated as the metal oxide, while preferred amounts range from 0.l% to 3.0% when metals other than antimony are used.

At the present, no satisfactory explanation can be given of the exact manner in which these after-treating salts protect and improve the metallated or titanated cellulose. The failure or degradation of the cellulose seems to be largely photochemical in character. However, degradation can also be observed upon product aging, even in the dark at elevated temperatures. In any case, the presence of the added salts and precipitated metal compounds minimizes or slows down or prevents degradation altogether. The precipitated metal compunds appear to act as a screen which protects the titanated cellulose from the actinic light rays and would account fully for the stabilization accomplished against purely photochemical degradation, However, a possible chemical or colloidal combination of the precipitated metals with the metallating or titanium compound, or the titanium cellulose complex, may induce an actual chemical change in the system to give rise to less photo chemically active substances and greater stability with time.

Many desirable advantages attend the present invention. Thus, one can obtain a higher, more desirable content of titanium in the product with antimony esters. For example, when mixtures of titanium and antimony esters are used in treating the amine swollen cellulose, it is rarely possible to get more than 20 or at most 25% of combined oxides into the cellulose. About equal weights of titanium dioxide and antimony trioxide give the best overall product. It is often desirable that around 20% of titanium dioxide be present. This can be accomplished herein by titanating the cellulose in the absence of antimony, and then later applying the metal salt treatment from an aqueous solution. This has economic advantages, since the other metal salts seem to be more eflicient than antimony in achieving desired stability, e.g., a lower content of cobalt oxide is required for the same stability than would be required for antimony trioxide. This usually makes possible certain economic advantages. When colored fabric, etc., are desired, very stable, clean, bright colors can be produced by my salt treatment.

While elevated or boiling temperatures can be used in the reaction of .the metal ester with the cellulose being treated, these are not essential.

The reaction can be accomplished at lower temperatures through the employment of longer contact time and may be considered to be at the discretion of the operator. The temperature used in removal of solvents after completion of the reactions is likewise flexible and one can employ any suitable vaporization conditions. The variable reaction times, temperature, pressure of the system when swelling and complexing as well as when reacting and tenderizing the swollen and complexed product by ester treatment, are dependent upon the character of the initial cellulose material, the physical attributes of the swelling agent and the degree of subsequent metallization or degree of change of physical and chemical properties desired. Hence, such conditions cannot be specifically set out for all individual cases. Where relatively low-boiling liquids are used, such as methylamine, either low temperature operation at atmospheric pressure, or higher temperature operation at a pressure sufficient to maintain the major portion of ammonia derivative in the liquid state, is required. Short times of contact in both complexing steps, particularly at sub-zero temperatures, are advantageous and effective. A minimum of about 30 minutes of contact is preferred in the first step, that is, swelling and complexing the cellulose with the ammonia derivative; while a minimum of about 15 minutes is preferred in the second complexing, or tenderizing step, during which addition and reaction is effected of the ester with the complexed cellulose. The reaction of the ester-ammonia-derivative-complexed cellulose intermediate with water depends on penetration, a period of about 15 minutes to an hour at room temperature being preferred for use in this step.

As already stated, the invention provides a novel modified cellulose textile having a novel combination of properties, including the single fiber and fabric characteristics of wool, increased liveliness, greater bulk, mildew resistance, crease and handle resistance, abrasion resistance, flame resistance, greater warmth and insulating characteristics, washability and high melting point. Having the crease resistance and resilience approaching that of wool, upon release after pressing, the fibers and textile will readily spring apart, a characteristic known as recovery. These attributes assure production of a material having desired 10ft (high bulk or volume for a given weight) properties which afford ready production of wool-like, open, porous fabrics of high covering power and thick, warm fabrics with a minimum of weight, qualities demanded in all apparel fabrics. Additionally, my modified product exhibits other improved characteristics, e.g., mildew resistance, abrasion resistance, extensibility, elasticity and flame resistance, to afford a unique combination of properties which assure essential texture, warmth, fit, and durability characteristics and thereby enhance its value for acceptance by textile manufacturers and the garment industry.

During the treatments, the strength of the cellulose material undergoing modification becomes poor and fabrics such as used in the above examples lose strength to such an extent that they are easily damaged by punctures and tears. It is believed that the cellulose is de generated under the conditions of the process by a breaking of the cross-linkage of cellulose. The titanium, or other metal, enters into combination with the cellulose and the anhydrous product has poor strength due to this lack of cross-linkage between molecular units of the cellulose fiber. Upon treatment with water, however, there is strong evidence that cross-linkage again takes place and the fabric resumes its original strength. The cross-linkage at this time is believed to be somewhat difierent and a new chemical bonding takes place through the titanium or other metal which has entered into the complex structure. The improved properties are believed to be due in large measure to this new cross-linkage or bonding both units of the cellulose structure. When the product has received normal washing, it is substantially nitrogen-free indicating a relatively pure metal-modified cellulosic material.

Other evidence of the existence of a chemical combination of treating metal with the cellulose resides in the excellent mildew resistance which the metallated, especially the titanated, cellulose exhibits. This result does not occur when recourse is had to precipitation of TiO in a cellulosic fabric from an aqueous solution.

I claim: a 1. A method for preparing a cellulose textile material possessing substantially the single fiber, liveliness, crease resistance and bulk characteristics of wool stabilized against photodegnadation, comprising reacting a cellulose textile material under anhydrous conditions in the presence of a nitrogenous chemical swelling agent for cellulose selected irom the group consisting of ammonia and amine compounds which swell the cellulose and form nitrogenous complexes with the cellulose and containing a radical selected from the group consisting of NH and NH, with a water hydrolyzable organic compound selected from the group consisting of (a) a metal ester corresponding to the formula Me(OR) wherein Me is a metal selected from the group consisting of titanium, zirconium, hafnium, thorium, aluminum, iron and antimony, which forms a water-insoluble oxide and has a valence selected from the group consisting of 3 and 4 and has a coordination number in the oxide state at least one greater than the valence, R is selected from the group consisting of hydrocarbon and chlorinated hydrocarbon radicals, and x corresponds to the valence of the metal, and (b) a condensed ester of said hydrolyzable metal ester resulting from the reaction of said ester with water, continuing said reaction until a highly tendered metal ester-amine cellulose intermediate product of said metal ester is formed of substantially reduced tensile and tear strength over that of the swollen cellulose textile obtained from said chemical swelling agent treatment, contacting said metal ester-amine cellulose product with aqueous media consisting essentially of water which regenerates and restores said product to substantially the tensile strength of the original untreated cellulose textile material, treating the resulting chemically modified cellulose product with an aqueous acidic solution of a stabilizing water soluble ionizable, acidic salt of a polyvalent heavy metal selected trom the group consisting of antimony, chromium, manganese, cobalt, nickel, bismuth, copper, tungsten and cerium, thereafter adjusting the pH of said acidic solution to substantial neutrality and to precipitate on the modified cellulose product a small amount of a water insoluble 10 compound selected from the group consisting of an oxide and hydroxide of said polyvalent heavy metal, and recovering the resulting stabilized product.

2. A method for preparing a cellulose textile material possessing substantially the single fiber, liveliness, crease resistance and bulk characteristics of wool stabilized against photodegradation, comprising reacting a cellulose textile material under anhydrous conditions in the presence of a nitrogenous chemical swelling agent for cellulose selected from the group consisting of ammonia and amine compounds which swell the cellulose and form nitrogenous complexes with the cellulose and containing a radical selected from the group consisting of NH and NH, with a water hydrolyzable organic compound selected from the group consisting of a metal ester corresponding to the formula Me(OR) wherein Me is a metal selected from the group consisting of titanium, zirconium, hafnium, thorium, aluminum, iron and antimony, which forms a water insoluble oxide and has a valence selected from the group consisting of 3 and 4 and has a coordination number in the oxide state at least one greater than the valence, R is selected from the group consisting of hydrocarbon and chlorinated hydrocarbon radicals, and x corresponds to the valence of the metal, continuing said reaction until a highly tendered metal ester-amine cellulose intermediate product of said metal ester is formed of substantially reduced tensile and tear strength over that of the swollen cellulose textile obtained from said chemical swelling agent treatment, immersing said metal ester-amine cellulose product in aqueous media consisting essentially of Water which regenerates and restores said product to substantially the tensile strength of the original untreated cellulose textile material, contacting the resulting chemically modified cellulose product containing in chemical combination with the cellulose from about 1% up to 40% of the metal of said ester with an aqueous acidic solution of a water soluble ionizable, acidic salt of a polyvalent heavy metal selected from the group consisting of antimony, chromium, manganese, cobalt, nickel, bismuth, copper, tungsten and cerium, thereafter adjusting the pH of said contacting acidic solution to substantial neutrality by incorporating an aqueous basic alkaline solution therein and to precipitate on said modified cellulose product from about .05 to 15%, calculated as the oxide, of a water insoluble compound selected from the group consisting of an oxide and hydroxide of said polyvalent heavy metal, and recovering the resulting stabilized product.

3. A method for preparing a cellulose textile material possessing substantially the single fiber, liveliness, crease resistance and bulk characteristics of wool stabilized against photodegradation, comprising reacting a cellulose textile material under anhydrous conditions in the presence of an alkyl amine chemical swelling agent for cellulose which swells the cellulose and forms nitrogenous complexes with cellulose with a water hydrolyzabl'e organic antimony ester corresponding to the formula Sb(OR) in which R is selected from the group consisting of hydrocarbon and chlorinated hydrocarbon radicals, continuing said reaction until a.highly tenderized metal ester-amine cellulose intermediate of said antimony oxide is obtained having a substantially reduced tensile and tear strength compared to the swollen cellulose textile obtained from said chemical swelling agent treatment, subjecting said tenderized intermediate to contact with aqueous media consisting essentially of water which regenerates and restores said cellulose intermediate to substantially the tensile strength of the original untreated textile material, treating the resulting modified product containing in chemical combination with the cellulose from about 5% to 35% of the metal of said ester with :an aqueous acidic solution of a water soluble ionizable, acidic salt of a polyvalent heavy metal selected from the group consisting of antimony, chromium, manganese, cobalt, nickel, bismuth, copper, tungsten, and cerium,

1 l thereafter adjusting the pH of said acidic solution to neutrality by incorporating therein an aqueous alkali solution and to precipitate on said product from about .1 to of a water insoluble compound selected from the group consisting of an oxide and hydroxide of said polyvalent heavy metal, and recovering the resulting product.

4. A method for preparing cellulose textile material possessing substantially the single fiber, liveliness, crease resistance and bulk characteristics of wool stabilized against photodegradation, comprising reacting a cellulose textile material under anhydrous conditions in the presence of an alkyl amine swelling agent for cellulose which swells the cellulose and forms nitrogenous complexes with cellulose, with a water hydrolyzable organic titanium ester corresponding to the formula Ti(OR) in which R is selected from the group consisting of hydrocarbon and chlorinated hydrocarbon radicals, continuing said reaction until a highly tenderized metal ester-amine cellulose intermediate of said titanium ester is obtained having a substantially reduced tensile and tear strength compared to the swollen cellulose textile obtained from said chemical swelling agent treatment, subjecting said tenderized intermediate to contact with aqueous media consisting essentially of water which regenerates and restores said cellulose intermediate to substantially the tensile strength of the original untreated textile material, treating the re sulting modified product containing in chemical combination with cellulose from about 5% up to 35% of the metal of said ester with an aqueous acidic solution of a water soluble ionizable, acidic salt of a polyvalent heavy metal selected from the. group consisting of antimony, chromium, manganese, cobalt, nickel, bismuth, copper, tungsten, and cerium, thereafter adjusting the pH of said acidic solution to neutrality by incorporating therein an aqueous alkali solution and to precipitate on said product from about .1 to 5% of a water insoluble compound selected from the group consisting of an oxide and hydroxide of said polyvalent heavy metal, calculated as the oxide, and recovering the resulting product.

5. A method for preparing a cellulose textile material possessing substantially the single fiber, liveliness, crease resistance and bulk characteristics of wool stabilized against photodegradation, comprising swelling a cellulose textile material by treatment under anhydrous conditions with an alkyl amine chemical swelling agent for cellulose which forms nitrogenous complexes with cellulose, subjecting the resulting amine-treated, swollen and nitrogenous complexed cellulose product to reaction under anhydrous conditions with a water hydrolyzable organic ester corresponding to the formula Me(OR) wherein Me is a metal selected from the group consisting of titanium, zirconium, hafnium, thorium, aluminum, iron and antimony, which forms a water insoluble oxide, has a valence selected from the group consisting of 3 and 4 and a coordination number in the oxide state at least one greater than the valence, R is an alkyl radical, and x corresponds to the valence of the metal, continuing said reaction until a highly tendered metal ester-amine intermediate of said metal ester is obtained, the tensile and tear strength of which is substantially reduced over that of the originally treated swollen cellulose textile, subjecting said intermediate product to contact with aqueous media consisting essentially of water which regenerates and restores said cellulose intermediate to substantially the tensile strength of the original untreated cellulose textile, contacting the resulting modified cellulose product containing in chemical combination with the cellulose from about 5% to 35% of the metal of said ester with an aqueous acidic solution of a water soluble ionizable, acidic salt of a polyvalent heavy metal selected from the group consisting of antimony, chromium, manganese, cobalt, tungsten, nickel, bismuth, copper, and cerium, thereafter adjusting the pH of said acidic solution to neutrality by incorporating therein an aqueous alkali solution and to precipitate on said product from about .1 to 5% of a water insoluble compound selected from the group consisting of an oxide and hydroxide of said polyvalent heavy metal, calculated as the oxide, and recovering the resulting product.

6. A method for preparing a cellulose textile material possessing substantially the single fiber, liveliness, crease resistance and bulk characteristics of wool stabilized against photodegradation, which comprises reacting a cellulose textile material under anhydrous conditions in the presence of an alkyl amine swelling agent for cellulose which swells the cellulose and forms nitrogenous complexes with the cellulose, with a mixture of an anhydrous water hydrolyzable alkyl ortho ester of a metal selected from the group consisting of titanium, zirconium, hafnium, thorium, aluminum, iron and antimony, continuing said reaction until a highly tenderized ester-amine cellulose intermediate of said metal ester forms of substantially reduced tensile and tear strength over the swollen cellulose textile obtained from said alkyl amine swelling agent treatment, subjecting said highly tender ized intermediate to contact with water to regenerate and restore said intermediate to substantially the tensile strength of the original untreated cellulose textile material, immersing the resulting modified cellulose product containing from 5% to 35% of the metal of said ester in a dilute, 1-20% aqueous acidic solution of a water soluble ionizable, acidic salt of a polyvalent heavy metal selected from the group consisting of antimony, chromium manganese, cobalt, nickel, bismuth, copper, tungsten, and cerium, thereafter adjusting the pH of said acidic solution to neutrality to precipitate on said product from about .1% to 5% of a water insoluble compound selected from the group consisting of an oxide and hydroxide of said polyvalent heavy metal, and recovering the resulting product.

7. A method for preparing a cellulose textile material possessing substantially the single fiber, liveliness, crease resistance and bulk characteristics of wool stabilized against photodegradation, comprising immersing a cellulose textile material in an anhydrous alkyl amine chemical swelling agent for cellulose which forms nitrogenous complexes with cellulose until a swollen nitrogenous complexed cellulose product is obtained, reacting said product at the boil and under anhydrous conditions with an organic solution of a water hydrolyzable alkyl ortho titanate until a highly tendered metal ester-amine cellulose intermediate of said titanate forms of substantially reduced tensile and tear strength over the swollen cellulose textile obtained from said chemical swelling agent treatment, removing under anhydrous conditions excess unreacted titanate reactant from said intermediate and subjecting the latter to contact with water which regenerates and restores said intermediate to substantially the tensile strength of the original untreated cellulose textile material, immersing the resulting product in a dilute, 1-20% acidic, aqueous solution of a water soluble ionizable, acidic salt of a polyvalent heavy metal selected from the group consisting of antimony, chromium, manganese, cobalt, nickel, bismuth, tungsten, copper and cerium, thereafter adjusting the pH of said acidic solution to neutrality to precipitate on said product from about .05 to 15% of an oxide of said heavy metal, and recovering the resulting stabilized chemically modified cellulose product.

8. A method for preparing a cellulose textile material possessing substantially the single fiber, liveliness, crease resistance and bulk characteristics of wool stabilized against photodegradation, comprising immersing a cellulose textile material in an anhydrous alkyl amine chemical swelling agent for cellulose which forms nitrogenous complexes with cellulose until a swollen nitrogenous complexed cellulose product is obtained, reacting said product at the boil and under anhydrous conditions with an organic solution of a water hydrolyzable alkyl ortho titanate and alkyl ortho antimonite until a highly tendered metal ester-amine cellulose intermediate of said titanate and antimonite forms of substantially reduced tensile and tear strength over the swollen cellulose textile obtained from said chemical swelling agent treatment, removing under anhydrous conditions excess unreacted titanate and antimonite reactant from said intermediate and contacting it with water which regenerates and restores said intermediate to substantially the tensile strength of the original untreated cellulose textile material, immersing the cregenerated product in a dilute, l20% acidic, aqueous solution of a Water soluble ionizable, acidic salt of a polyvalent heavy metal selected from the group consisting of antimony, chromium, manganese, cobalt, nickel, bismuth, tungsten, copper and cerium, thereafter adjusting the pH of said acidic salt solution to neutrality by alkali addition to precipitate on said product from .05 to 15% of an oxide of said heavy metal, and recoverng the resulting stabilized chemically modified cellulose product.

9. A method for preparing a stabilized cellulose textile material possessing substantially the single fiber, liveliness, crease resistance and bulk characteristics of wool, comprising immersing a cellulose textile material in an anhydrous alkyl amine chemical swelling agent for cellulose which forms nitrogenous complexes with cellulose and until a swollen nitrogenous complexed cellulose product is obtained, reacting said product under anhydrous conditions and at the boil with an anhydrous organic solution of a water hydrolyzable alkyl ortho zirconate until a highly tendered metal ester-amine cellulos intermediate forms of substantially reduced tensile and tear strength over the swollen cellulose textile obtained from said chemical swelling agent treatment, removing under anhydrous conditions excess unreacted zirconate reactant from said intermediate and subjecting it to contact with water which regenerates and restores said intermediate to substantially the tensile strength of the original untreated cellulose textile material, immersing the regenerated product in a dilute, 120% acidic, aqueous solution of a water soluble ionizable, acidic salt of a polyvalent heavy metal selected from the group consisting of antimony, chromium, manganese, cobalt, nickel, bismuth, tungsten, copper and cerium, thereafter adjusting the pH of said acidic salt solution to neutrality by alkali addition to precipitate on said product from .05 to 15% of an oxide of said heavy metal, and recovering the resulting stabilized chemically modified cellulose product.

10. A method for preparing a stabilized cellulose textile material possessing substantially the single fiber, liveliness, crease resistance and bulk characteristics of wool, comprising immersing a cellulose textile material in an anhydrous alkyl amine chemical swelling agent for cellulose which forms nitrogenous complexes with cellulose and until a swollen nitrogenous complexed cellulose product is obtained, reacting said product under anhydrous conditions at the boil with an organic solution of Water hydrolyzable isopropyl ortho titanate until a high- 1y tendered metal ester-amine cellulose intermediate forms of substantially reduced tensile and tear strength over the swollen cellulose textile obtained from said chemical swelling agent treatment, removing under anhydrous conditions excess unreacted titanate from said intermediate and contacting it with Water which regenerates and restores said intermediate to substantially the tensile strength of the original untreated cellulose textile material, immersing the resulting product in a 120% acidic, aqueous solution of a water soluble acidic antimony salt, adjusting the pH of said acidic solution to neutrality by alkali addition to precipitate -l2% of Sb O on said product, and recovering the resulting stabilized chemically modified cellulose product.

11. A method for preparing a stabilized cellulose textile material possessing substantially the single fiber, liveliness, crease resistance and bulk characteristics of wool, comprising immersing a cellulose textile material in an anhydrous alkyl amine chemical swelling agent for cellulose which forms nitrogenous complexes with cellulose 14 and 'until a swollen nitrogenous complexed cellulose product is obtained, reacting the swollen product under anhydrous conditions at the boil with an anhydrous organic solvent solution of water hydrolyzable isopropyl ortho titanate until a highly tendered metal ester-amine cellulose intermediate forms, the tensile and tear strength of which is substantially reduced over that of the swollen cellulose textile obtained from said chemical swelling agent treatment, subjecting said intermediate to contact with water which regenerates and restores the intermediate to substantially the tensile strength of the original untreated cellulose textile material, immersing the resulting product in a l20% acidic, aqueous solution of a water soluble acidic salt of chromium, adjusting the pH of said acidic solution to neutrality by alkali addition to precipitate on said product from .05 to 15%, calculated as the oxide, of an insoluble chromium compound selected from the group consisting of an oxide and hydroxide, and recovering the resulting stabilized chemically modified cellulose product.

12. A method for preparing a stabilized cellulose textile material possessing substantially the single fiber, liveliness, crease resistance and bulk characteristics of wool, comprising immersing a cellulose textile material in an anhydrous alkyl amine chemical swelling agent for cellulose which forms nitrogenous complexes with cellulose and until a swollen nitrogenous complexed cellulose product is obtained, reacting the swollen product under anhydrous conditions at the boil with an anhydrous organic solvent solution of water hydrolyzable isopropyl ortho titanate until a highly tendered metal ester-amine cellulose intermediate forms, the tensile and tear strength of which is substantially reduced over that of the swollen cellulose textile obtained from said chemical swelling agent treatment, subjecting said intermediate to contact with water which regenerates and restores the intermediate to substantially the tensile strength of the original untreated cellulose textile material, immersing the resulting product in a l20% acidic, aqueous solution of a water soluble acidic salt of cobalt, adjusting the pH of said acidic solution to neutrality by alkali addition to precipitate on said product from .05 to 15%, calculated as the oxide, of an insoluble cobalt compound selected from the group consisting of an oxide and hydroxide, and recovering the resulting stabilized chemically modified cellulose product.

13. A method for preparing a stabilized cellulose textile material possessing substantially the single fiber, liveliness, crease resistance and bulk characteristics of wool, comprising immersing a cellulose textile material in an anhydrous alkyl amine chemical swelling agent for cellulose which forms nitrogenous complexes with cellulose and until a swollen nitrogenous complexed cellulose product is obtained, reacting the swollen product under anhydrous conditions at the boil with an anhydrous organic solvent solution of Water hydrolyzable isopropyl ortho titanate until a highly tendered metal ester-amine cellulose intermediate forms, the tensile and tear strength of which is substantially reduced over that of the swollen cellulose textile obtained from said chemical swelling agent treatment, subjecting said intermediate to contact with water which regenerates and restores the intermediate to substantially the tensile strength of the original untreated cellulose textile material, immersing the resulting product in a 120% acidic, aqueous solution of a water soluble acidic salt of copper, adjusting the pH of said acidic solution to neutrality by alkali addition to precipitate on said product from .05 to 15%, calculated as the oxide, of an insoluble copper compound selected from the group consisting of an oxide and hydroxide, and recovering the resulting stabilized chemically modified cellulose product.

14. A method for preparing a stabilized cellulose textile material possessing substantially the single fiber, liveliness, crease resistance and bulk characteristics of wool,

comprising immersing a cellulose textile material in an anhydrous alkyl amine chemical swelling agent for cellulose which forms nitrogenous complexes with cellulose and until a swollen nitrogenous complexed cellulose product is obtained, reacting the swollen product under anhydrous conditions at the boil with an anhydrous organic solvent solution of Water hydrolyzable isopropyl titanate and water hydrolyza ble isopropyl ortho antimonite until a higher tendered metal ester-amine cellulose intermediate forms, the tensile and tear strength of which is substantially reduced over that of the swollen cellulose textile obtained from said chemical swelling agent treatment, subjecting said intermediate to contact with water which regenerates and restores the intermediate to substantially the tensile strength of the original untreated cellulose textile material, immersing the resulting product in a l20% acidic, aqueous solution of a water soluble acidic antimony salt, adjusting the pH of said acidic solution to neutrality by alkali addition to precipitate on said product from 5l2% of Sb O and recovering the resulting stabilized chemically modified cellulose product.

References Cited in the file of this patent UNITED STATES PATENTS OTHER REFERENCES Balthis: Abstract of application S.N. 692,385, May 16, 1950, 634 O.G. 985.

Speer: Industrial and Engineering Chem., March 1950, pp. 440444.

Gulledge: Industrial and Engineering Chem, March l950, pp. 394 and 395.

Moncrieif: Textile Colourist & Finisher, August 1950,

pub.

20 pp. 394 and 395. 

1. A METHOD FOR PREPARING A CELLULOSE TEXILE MATERIAL POSSESSING SUBSTANTIALLY THE SINGLE FIBER, LIVELINESS, CREASE RESISTANCE AND BULK CHARACTERISTICS OF WOOL STABILIZED AGAINST PHOTODERGRADATION, COMPRISING REACTING A CELLULOSE TEXILE MATAERIAL UNDER ANHYDROUS CONDITIONS IS THE PRESENCE OF A NITROGENOUS CHEMICAL SWELLING AGENT FOR CELLULOSE SELECTED FROM THE GROUP CONSISTING OF AMMONIA AND AMINE COMPOUNS WHICH SWELL THE CELLULOSE AND FORM NITROGENOUS COMPLEXES WITH THE CELLULOSE AND CONTAINING A RADICAL SELECTED FROM THE GRAOUP CONSISTING OF -NH2 AND >NH, WITH A WATER HYDROLYZABLE ORGANIC COMPOUND SELECTED FROM THE GROUP CONSISTING OF (A) A METAL ESTER CORRESPOND TO THE FORMULA ME(OR)X WHEREIN ME IS A METAL SELECTED FROM THE GROUP CONSISTING OF TITANIUM, ZIRCONIUM, HAFNIUM, THORIUM, ALUMINUM, IRON AND ANTIMONY, WHICH FORMS A WATER-INSOLUBLE OXIDE AND HAS A VALENCE SELECTED FROM THE GROUP CONSISTING OF 3 AND 4 AND HAS A COORDINATION NUMBER IN THE OXIDE STATE AT LEAST ONE GREATER THAN THE VALENCE, R IS SELECTED FROM THE GROUP CONSISTING OF HYDROCARABON AND CHLORINATED HYDROCARBON RADICALS, AND X CORRESPONDS TO THE VALENCE OF THE METAL, AND (B) A CONDENSED ESTER OF SAID HYDROLYZABLE METAL ESTER RESULTING FROM THE REACTION OF SAID ESTER WITH WATER CONTINUING SAID REACTION UNTIL A HIGHLY TENDERED METAL ESTER-AMINE CELLULOSE INTERMEDIATE PRODUCT OF SAID METAL ESTER IS FORMED OF SUBSTANTIALLY REDUCED TENSILE AND TEAR STRAENGTH OVER THAT OF THE SWOLLEN CELLULOSE TEXTILE OBTAINED FROM SAID CHEMICAL SWELLING AGENT TREATMENT, CONTACTING SAID METAL ESTER-AMINE CELLULOSE PRODUCT WITH AQUEOUS MEDIA CONSISTING ESSENTIALLY OF WATER WHCIH REGENERATES AND RESTORES SAID PRODUCT TO SUBSTANTIALLY THE TENSILE STRENGTH OF THE ORGINAL UNTREATED CELLULOSE TEXTILE MATERIAL, TREATING THE RESULTING CHEMICALLY MODIFIED CELLULOSE PRODUCT WITH AN AQUEOUS ACIDIC SOLUTION OF A STABILIZING WATER SOLUBLE IONIZABLE, ACIDIC SALT OF A POLYVALENT HEAVY METAL SELECTED FROM THE GROUP CONSISTING OF ANTIMONY, CHROMIUM, MANGANESE, COBALT, NICKEL, BISMUTH, COPPER, TUNGSTEN AND CERIUM, THEREAFTER ADJUSTING THE PH OF SAID ACIDIC SOLUTION TO SUBSTANTIAL NEUTRALITY AND TO PRECIPITATE ON THE MODIFIED CELLULOSE PRODUCT A SMALL AMOUNT OF A WATER INSOLUBLE COMPOUND SELECTED FROM THE GROUP CONSISTING OF AN OXIDE AND HYDROXIDE OF SAID POLYVALENT HEAVY METAL, AND RECOVERING THE RESULTING STABILIZED PRODUCT. 